An apparatus and method for measuring hemodynamic parameters includes a sound velocity sensor coupled to at least one of an arterial or venous portion of a blood system. An indicator medium is injected into the blood system upstream of the sensor to dilute the bloodstream, and the sensor detects the...http://www.google.com/patents/US5453576?utm_source=gb-gplus-sharePatent US5453576 - Cardiovascular measurements by sound velocity dilution
